Well packer



Nov. 1, 1966 J. D. MOTT 3,282,342

WELL PACKER Filed Nov. 21, 1963 4 Sheets-Sheet 1 MOTT R.

Nov. 1, 1966 J. D. MOTT 3,282,342

' WELL PACKER Filed Nov. 21, 1963 4 Sheets-Sheet 2 40 336 /Z& 33 c 42 4Nov. 1, 1966 J. D. MOTT 3,282,342

WELL PACKER Filed Nov. 21, 1965 4 Sheets-Sheet 5 JAM/5 0. MOT7' IN VENTOR.

J. D. MOTT WELL PACKER Nov. 1, 1966 Filed Nov. 21. 1963 4 Sheets-Sheet 4JAMES D. 0

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ATTORNE United States Patent 3,282,342 WELL PACKER James D. Mott,Houston, Tex., assignor to C. C. Brown Filed Nov. 21, 1963, Ser. No.325,435 12 Claims. ((11. 166-120) This invention relates to new anduseful improvements in well packer assemblies. More particularly theinvention relates to improvements in a well packer assembly having dualanchoring means for anchoring the assembly movement in either directionwithin a well bore.

Well packer devices having means for locking the device within a wellbore or casing and capable of anchoring said device against a pressuredifferential from either above or below the device have come intogeneral use. These devices require the use of a dual anchoring means,one for anchoring against upward movement and the other for anchoringagainst downward movement; also, since the well packer device must beremovable, problems are presented in connection with the provision ofthe necessary dual anchoring means which must be set for positiveanchoring action and yet must be readily releasable.

Various types of dual anchor, releasable well packer devices have beenemployed and one example is illustrated in the co-pending application ofCicero C. Brown, Serial No. 784,503, filed January 2, 1959, nowabandoned in favor of continuation-in-part application, Serial No.69,118 which has matured into Patent No. 3,142,338, wherein release ofthe dual anchoring means is elfected mechanically by rotation of thetubing string on which the assembly is mounted. This is a satisfactorystructure and normally accomplishes the purpose but because release isdependent upon the tubing rotation operating a threaded connection, rustand corrosion may jam the threaded connection and make releasedifficult.

Other types of dual anchor, releasable packer devices have been employedwherein the setting and release of the anchoring means and the sealingelement of the device is accomplished hydraulically; one example of thistype is shown in the co-pending application of Cicero C. Brown et al.,Serial No. 69,168, filed November 14, 1960, now Patent No. 3,122,205.While eliminating the disadvantages inherent in the mechanicallyreleasable type, the hydraulic releasable device, being dependent uponseals in the hydraulic system may give difficulty if the seals fail dueto age or for other reasons.

It is therefore one object of this invention to provide a well packerassembly having upper and lower anchoring means which may be set byhydraulic pressure and which is adapted to be released by firstreleasing the lower anchoring means by hydraulic pressure followed by adirect upward movement of the tubing or pipe on which the assembly ismounted to effect a release of the upper anchoring means to permitremoval of the device.

An important object of this invention is to provide a Well packerassembly having upper and lower anchoring means which are settable inresponse to pressure; the structure being arranged so that the loweranchoring means is adapted to be released responsive to hydraulicpressure but which includes a mechanical means for releasing the packer,the latter being operable in the event' that the hydraulic release failsto function properly, whereby removal of the assembly from the well isassured.

Another object of this invention is to provide a well packer assembly ofthe character described which may be hydraulically set and whichincludes a latch mechanism associated with release means for unsettingsaid assembly; said latch mechanism functioning to permit a mechanicalrelease through manipulation of a well pipe on which the assembly ismounted in'the event the hydraulic unsetting means fails to functionproperly to unset the assembly.

A further object of the present invention is to provide a well packerassembly which may be hydraulically set and released wherein a latchmechanism is incorporated in the release system which maintains a directmechanical connection between the assembly and the pipe string in theevent the hydraulic release means fails to operate, whereby release maybe accomplished mechanically by manipulation of the pipe string.

These and other objects of the present invention will be readilyunderstood from the following explanation and description of the detailsof the device which are illustrated in the accompanying drawingswherein:

FIGURE 1 is a view partly in section and partly in elevation of a wellpacker assembly, constructed in accor-dance with the invention andillustrating the various parts in the positions they assume duringlowering of the assembly into the well bore.

FIGURE 2 is a similar view showing the packer in the fully set andanchored position in the well bore.

FIGURE 3 is a similar view illustrating the packer in a partially unsetposition with the lower sealing and anchor elements released.

FIGURE 4 is a similar view showing the packer in fully releasedposition.

FIGURE 5 is a similar view illustrating the packer in a partially unsetposition showing the anchor elements set and the sealing elementsreleased by rotation of the tubing.

FIGURE 6 is a similar view illustrating the packer fully released byrotation of the tubing.

FIGURE 7 is a horizontal cross-sectional view taken on line 77 of FIGURE1.

FIGURE 8 is a horizontal cross-sectional view taken on line 8-8 ofFIGURE 1.

FIGURE 9 is a horizontal cross-sectional view taken on line 99 of FIGURE1.

FIGURE 10 is a horizontal cross-sectional view taken on line 1010 ofFIGURE 3.

FIGURE 11 is a fragmentary sectional view enlarged from FIGURE 1.

In the drawings the letter T designates the usual well tubing or pipestring which extends downwardly through a well casing 10 within a wellbore W. The improved well tool assembly which is herein shown anddescribed as a well packer assembly is generally indicated by the letterP, FIGURE 1, and is connected at the desired point in the tubing or pipestring T. Tubing T is suspended from the usual tubing head which formspart of the surface control equipment (not shown) and the usual flowcontrol valve is disposed in the upper end of the tubing T to controlflow therethrough.

The packer assembly P is adapted to be lowered into proper positionwithin the well casing 10 by means of the tubing T and during suchlowening the packer is in the unset position. After reaching the desiredelevation within the casing, the control head equipment is properlymounted to close in the upper end of said casing and at this time thewell is under control. Then the well fluids may be circulated to bringthe well in. Thereafter, the packer assembly P may be moved into set orsealing position by blocking off the lower end of the tubing string andby the application of :a hydraulic pres-sure through the bore of thetubing T. After the packer assembly is set, flow of the well fluids fromthe producing formation below said assembly is upwardly through thetubing T.

When it is desired to remove the packer assembly P and the tubing T, thepacker assembly P is moved into a released or unset position by theapplication of a fluid pressure through the bore of the tubing T. Aswill be described, the packer assembly is one which can be set byhydraulic pressure and can be released or unset by hydraulic pressure,whereby no movement or manipulation of the tubing T is required to:efiect said release. This provides the very decided advantage ofpermitting the control head equipment to remain in place at all times sothat the well is completely under control both during setting orreleasing of the assembly. Additionally, the invention prov-ides amechanical release means which may be actuated in case the hydraulicrelease mechanism fails. The arrangement is such that the mechanicalrerelease means is actuated by manipulating the tubing T, suchmanipulation preferably being a right-hand rotation of said tubing.

The well packer assembly includes :a central support or mandrel 12 whichcomprises an upper tubular section 12a and a lower tubular section 12b.The sections 12a and 12b are connected together in telescopingrelationship by relatively coarse buttress thread 13 which arepreferably left-hand threads. With such arrangement, when the lowertubular section 121) is held against rotation, a right-hand rotation ofupper tubular section 12a will result in moving the sections axially ina direction to separate said sections. The upper section 12a is providedwith spaced external upwardly facing shoulders 14 and 14a which areabove the threaded area 13 while the section 12b is formed with spacedexternal downwardly facing shoulders 15 and 15a which are on the lowerportion of said section. These shoulders properly locate the units andelements which are mounted on the central support, a will hereinafter beexplained.

The threaded connection between the upper tubular section 12a and thelower tubular section 1212 is formed by the male thread 13a on uppertubular section 12a and the female thread 13b formed in arcuate segmentmembers 16 which are confined in windows 17 cut through the upperportion of lower tubular section 12b (FIGURES 8 and 11). There is shownthree segment members 16 and three corresponding confining windows 17 tohold them, although any number of segment members and a correspondingnumber of windows might be used. The segment members 16 are held inthreaded engagement with the male thread 13a on upper tubular section12a by a cylindrical releasing ring 18. Spaced projections 18a on thewall of the bore of releasing ring 18 (FIG. 11) register with opposingspaced projections 16a on the exterior of arcuate segment members 16 andhold the segmented members in threaded engagement with threads 13a onupper tubular section 12a. Spaced grooves 13b formed in the bore ofreleasing ring 18 are adapted, when ring 18 and segment members 16 aremoved relative to each other, to register with the spaced projections16a on segment members 16 whereby segment members may undergo radiallyoutward movement and disengage their threads 13b from threads 13a ofsaid upper tubular section 12a. FIGURE 10 illustrates the disengagementof the threads. while the engaged position is shown in FIGURE 8.

Releasing ring 18 is connected by a shear pin 19 to each segment member16 and prevents relative movement of the ring with respect to thesegments to maintain the threads 1311 on segment members 16 inengagement with threads 13a on upper tubular section 12a. Shear pin 19in cooperation with segment members 16, windows 17 and releasing ring 18comprise a latch mechanism which maintains the mechanical releasemechanism in operating condition. As will be explained, shearing of pin19 will occur when the hydraulic releasing system, which is hereinafterdescribed, is actuated; if for any reason such as seal failure thehydraulic releasing system does not function properly, the ring 18 andsegment members 16 remain connected so that the segments maintainthreaded connection with the mandrel section to preserve the operabilityof the mechanical release mechanism. Sufficient space is providedbetween shoulder 13c on release ring 18 and shoulder 120 on the upperend of lower tubular section 12b to facilitate movement of release ring18 from the engaged position to the released position. The O-ring seal26 seals oif between releasing ring 18 and lower tubular section 12b.

Upper anchoring and sealing unit C surrounds upper tubular section 12aof mandrel 12 and comprises upper seal body 21, bearing retainer 22,packing member 24, upper cone member 25, upper slips 26 and upper slipholder 27. Upper seal body 21 is threadedly engaged with bearingretainer 22 and sealed therewith by seal 23 and has a lower dependingtubular portion 21a in sliding relation to the exterior of upper tubularsection 12a and downwardly facing shoulder 21b engaging the upperportion of packing element 24. The upper portion of upper cone member 25engages the lower portion of packing element 24. Upper slips 26 and haveT hangers 26a which engage T slots 27a in upper slip holder 2'7. Pins 28extend through upper cone member 25 into slots 210 in portion 21a ofupper seal body 21. Upper cone member 25 is provided with inclinedsurfaces 25a on which upper slips 26 will siide causing upper slips 26to move outward when moved upward. Upward movement of upper slip holder27 responsive to pressure as hereinafter more fully described, willcause upper slips 26 to move upward and because of inclined surfaces 25aon upper cone member 25 to move outward to engage the interior of wellcasing 18. Such movement will also cause upper cone member 25 to moveupward thereby compressing packing element 24 between the upper portionof upper cone member 25' and shoulder 21b on upper seal body 21. Theexterior of portion 21a of upper seal body 21 will support packingmember 24 when compressed whereby compression of packing element 24 willprovide a seal against the interior of well casing 113 as shown inFIGURE 2.

Lower anchoring and sealing unit D surrounds lower tubular section 12bof mandrel 12 and comprises lower seal body 29, packing element St lowercone member 31, lower slips 32 and lower slip holder 33. Lower seal body29 is held in position on lower tubular section 12b by lower connection34 and ring 35 positioned in groove 36 in the exterior of lower tubularsection 12b. Lower seal body 29 is provided with a recess having upwardfacing shoulder 29a which engages packing element 30. Lower cone member31 engages the upper portion of packing element 30 and has inclinedsurfaces 31a engaging lower slips 32 in sliding engagement. Lower slips32 are provided with T hangers 32a which engage T slots 33a in lowerslip holder 33. Lower slip holder 33, as shown in FIGURE 1, isreleasably connected to cylinder 3'? by shear pin 38 and has its upperportion 33b within cylinder 37 and sealed thereto by seal 39 for slidingengagement therewith.

Guide pins 49 extend through cylinder 37 into slots 3c in upper portion33b of lower slip holder 33. Guide pins 41 extend through upper portion33b of lower slip holder 33 into slots 42 in the exterior of lowertubular section 12b.

Upper anchoring and sealing unit C is restrained at its upper portionand can be actuated by pressure whereby upper slip holder 2'7 will beforced upward and lower anchoring and sealing unit C is restrained atits lower portion and can be actuated by pressure whereby lower slipholder 33 will be forced downward. The pressure causing such movement ofthe units C and D is transmitted from the interior of mandrel 12 throughports 43 in upper tubular section 12a and ports 44 in the lower tubularsec tion 1211. Since the pressure transmitted through both sets of portswill be the same the actuation of units C and D by hydraulic pressurewill not disturb the latch mechanism which comprises segments 15 withinwindows 17 which are pinned to releasing ring 18 by shear pin 19.

When the latch mechanism remains undisturbed the mechanical release ofWell packer assembly P is preserved. The latch mechanism will only bedisturbed when the assembly is hydraulically released as hereinaftermore fully explained. Such hydraulic release will release the latchmechanism only if the hydraulic release is functioning properly.

In operation the well packer assembly P is made up on tubing T and runto the depth within the casing where it is desired to be set. The usualtubing head equipment (not shown), is then installed at which time thepacker is suspended unset Within the casing as in FIGURE 1. Next asetting plug or ball 45 is dropped into the tubing and pumped to itsseat S as shown in FIGURE 2. Well fluids under pressure are pumpedthrough tubing T and enter.

the packer through ports 43 and 44 into chambers 46 and 47. It can beseen that this fluid pressure acts on both sides of the releasing ring18 so that there is no differential or tendency to shear the piri 19.The pressure acts in both chambers 46 and 47 to move the anchor and sealunits C and D into set position as shown in FIGURE 2 and as hereinaftermore fully explained.

The fluid pressure will be retained within chamber 46 by seal 48 againstthe exterior surface of upper tubular section 12a and seal 49 whichseals the threaded connection between upper slip holder 27 and cylinder37. The fluid pressure will be retained within chamber 47 by seal 39against the interior of cylinder 37 and by seal 55 against the exteriorof lower tubular section 1211. The fluid pressure contained withinchamber 46 and 47 will be suflicient to shear frangible shear pin 38,cause upper slip holder 27 and cylinder 37 to move upward and causelower slip holder 33 to move downward. The upward movement of upper slipholder 27 forces upper slips 26 upward on upper cone member 25 wherebyslips 26 are forced outward into engagement with the interior of casingby inclined surfaces 25a. Slips 26 are constructed to slide upward eventhough engaged with casing 1th but to resist a downward force. Thuscontinued upward movement of slip holder 27 will move upper cone member25 upward thereby compressing packing element 24 against shoulder 21b ofupper seal body 21 whereby a packing seal is provided against theinterior of well casing 10. The downward movement of lower slip holder33 forces lower slips 32 downward on lower cone member 31 whereby slips32 are forced outward into engagement with the interior of wall casing16 by inclined surfaces 31a. Slips 32 are constructed to slide downwardeven though engaged with casing 10 but to resist an upward force.Therefore continued downward movement of lower slip holder 33 will movelower cone member 31 downward thereby compressing packing element 30against shoulder 29a of lower seal body 29 whereby a packing seal isrovided against the interior of well casing 10'. When well packerassembly P is set the release of pressure within chambers 46 and 47 willnot release the units C and D as depending tubular portion 21a of upperseal body 21 and shoulder 29a are fixed to slips 26 and 32 which becauseof their tooth construction will not move when they have been set.Therefore, the units C and D will remain set even after pressure isreleased. Thereafter ball 45 will be pumped to the surface with the wellproduction through tubing T.

With well packer assembly P being thus set, it will hold a differentialpressure exerted either from above or below. If the higher pressure isbelow well packer assembly P lower anchoring and packing unit D willhold the pressure and maintain the position and if the higher pressureis above well packer assembly P upper anchoring and packing unit C willhold the pressure and maintain the position of the device. Anydifferential pressure will act against the seals which will transmit theforce to the cones further urging the slips into tighter engagement.

If it is desired to release we'll packer assembly P, it may be donehydraulically or mechanically but for any 6 release the production willof necessity have to be ceased. To release the packer hydraulically aspecial plug F is dropped into the tubing T and pumped into engagementwith seat S as shown in FIGURES 4 and 5. Seal 50 on plug F seals againstthe interior of tubular section 12a. This seal is between the ports 43and 44 so that fluid under pressure pumped down tubing T above plug Fwill flow through port 43 into chamber 46. The fluid pressure in chamber46 will be exerted downward on releasing ring 18 and with no balancingpressure in chamber 47 shear pin 19 will shear because segment members16 are restrained by threads 13. Release ring 18 will be pumped to thereleased position where the grooves 18b will register with projections16a on segment members 16 allowing threads 13b on segment members 16 todisengage from threads 13a on tubular section 12a. The fluid pressure inchamber 46 will force lower tubular section 1212 downward relative totubular section 12a causing packing member 30 to release. With continueddownward movement of tubular section 12b shoulder 15 abuts the end oflower cone member 31 and causes it to be moved from the grippingelements or slips 32 thus releasing the lower anchor and seal unit D.Since pin 19 will not shear unless the hydraulic release mechanism isoperating properly the loss of the mechanical release mechanism by theunlatching will not be of con-.

cern as the unlatching assures that the hydraulic release mechanism hasoperated properly.

With lower anchor and seal unit D in released position, tubing T islifted at the surface to provide release of upper anchor and seal unitC. This lift is assisted by an upward force due to pressure acting onthe difference in areas of seals 48 and 51 on upper tubular sections12a. The lifting of upper tubular section 12a will cause shoulder 14 onthe upper exterior portion of section 12a to engage bearing ring 52which will lift bearing rings 52 and 53, bearing retainer 22 and upperseal body 21. As upper seal body 21 is lifted packing element 24 will berelieved of compression and will return to its unset position shown inFIGURE 4. Further lifting of upper seal body 21 will cause pins 28 toengage the lower end of slots 21c whereby upper cone member 25 is pulledfrom "under upper slips 26. This will cause slips 26 to retract therebycompleting the release of upper anchor and seal unit C and allow tubingT to be pulled from the hole with well packer assembly P suspendedtherefrom.

It should be noted that when the well packer assembly P has beencompletely released that seal 51 will be positioned opposite 'by-passgroove 54. In this position seal 51 will no longer seal between thelower end of upper tubular section 12a and lower tubular section 12b andtherefore fluid within chamber 46 and fluid within well tubing T aboveports 43 will drain through the bypass thereby created. This provides abypass for the fluids to drain into the hole below well packer assemblyP while the tubing T is being pulled. This by-pass is uncovered wheneverwell packer assembly P is completely released whether it is donehydraulically or mechanically.

If for any reason, such as the clogging of ports 43 or failure of seals29, 48, 49, 51 or 56, well packer assembly P cannot be releasedhydraulically or if it is desired to be released mechanically then thismay be accomplished by rotation of tubing T to the right. Lower tubularsection 12b is held stationary in reference to rotational movement bypin 41 held by lower slip holder 33 in groove 42. Lower slip holder 33is in turn held against rotational movement by connection with the setslips 32 and also by pin 40 through cylinder 37 projecting into groove330, as cylinder 37 is connected through upper slip holder 27 to the setslips. 26. When tubing T is rotated to the right, left-hand threads 13aand 13!: cause lower tubular section 12b to move downward. This downwardmovement will first move lower seal body 29 downward by ring 35 engagingthe lower seal body 29 and the movement of lower seal body 29 will beaway from lower cone member 31 allowing packing element 30 to berelieved and return to its uncompressed position as shown in FIGURE 5.Additional movement of lower tubular section 121) will cause shoulder 15to engage lower cone member 31 pushing it downward and therebyretracting slips 32. In this position lower anchor and seal unit D isfully released. Release of upper anchor and seal unit C is accomplishedthereafter by continuing the right-hand rotation of tubing T. Lowertubular section 12b will be held against rotation by its connection(pins 40 and 41) with upper slips 26 which remain set. After unit D isreleased, the upper end of slot 330 will engage .pin 40 and furtherdownward movement of lower tubular section 12a will be prevented byslips 26. Therefore continued rotation of tubing T will cause uppertubular section 1211 and tubing T to move upward. This upward movementwill release packing element 3%) and further upward movement willrelease upper slips 26 in the same manner as herein'before described inrelation to the release of upper anchor and seal unit C subsequent tothe hydraulic release of lower anchor and seal unit D. With well packerassembly P completely released tubing T may be pulled from the hole withwell packer assembly suspended therefrom.

From the foregoing it may be seen that the present invention provides awell packer assembly having upper and lower anchoring and sealing units,both of which may be set hydraulically responsive to tubing pressure inposition within a well bore. The packer assembly provides a latchingmechanism with a shear pin which has to be sheared responsive to tubingpressure to unlatch and allow a hydraulic release. The packer assemblyfurther provides the shear pin for the latching mechanism which willprevent release of the latching mechanism in the event of a failurewhich will prevent proper operation of the hydraulic release. Suchlatching mechanism will preserve the mechanical release of the wellpacker device allowing ready removal of the device from the well bore.

The foregoing disclosure and description of the inven tion isillustrative and explanatory thereof and various changes in the size,shape, and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

1 claim:

1. A well packer assembly for connection in a well bore including,

an upper tubular section,

an upper abutment secured to said upper tubular section,

a lower tubular section,

a lower abutment secured to said lower tubular section,

said upper and said lower tubular sections connected by hydraulicallyreleasable threaded means,

an upper anchor and seal unit mounted below said upper abutment,

a lower anchor and seal unit mounted above said lower abutment,

hydraulically-actuated setting means between said upper and said loweranchor and seal units, and

means supplying fluid pressure to said hydraulicallyactuated means forsetting said upper and said lower anchor and seal units,

said hydraulically releasable threaded means being responsive to fluidpressure for disengagement of the threads and to unset said lower anchorand seal unit,

2. A well packer assembly for connection in a well bore according toclaim 1 including,

means releasably locking said hydraulically-actuated setting meanswhereby setting of said upper and said lower anchor and seal units isprevented until said locking means is released,

3. A well packer assembly for connection in a well bore according toclaim 1 including,

means releasably locking said hydraulically releasable threaded meanspreventing disengagement of the threads until said locking means isreleased.

4. A well packer assembly for connection in a well bore according toclaim 1 including,

a by-pass communication and means sealing said by-pass communicationuntil said assembly has been competely released.

5. A well packer assembly for connection in a well bore as set forth inclaim 1, together with means nonrotatably connecting the lower anchorand seal unit to said lower tubular section so that when said unit is inset position, the lower tubular section is restrained against rotationalmovement,

a conduit secured to the upper tubular section and extending to thesurface of the well bore whereby rotation may be imparted to said uppertubular section relative to the lower tubular section when the loweranchor and seal section is in set position, and

said relative rotation operating through said threaded means prior tohydraulic release of the threaded means to cause the tubular sections tomove in an axial direction which moves the lower abutment away from theupper abutment to thereby release the lower anchor and seal unit fromits set position.

6. A well packer assembly adapted to be lowered on a tubing and anchoredwithin a well bore including,

an upper tubular section connected to the tubing and having externalthreads at its lower portion,

an upper external abutment on the upper portion of the upper section,

an upper anchor and seal unit surrounding the upper section and disposedimmediately below the upper abutment,

a lower tubular section, a lower external abutment on said lowersectiton,

a lower anchor and seal unit surrounding said lower section and disposedimmediately above said lower abutment,

threaded means engageable with the lower tubular section and havingthreaded connection with the threads on the upper tubular section,

a piston and cylinder means surrounding the tubular sections andpositioned between the upper and lower anchor and seal units andcoacting therewith to set the units when said piston and cylinder meansis actuated,

communication means through each tubular section establishingcommunication between the bore of the sections and said piston andcylinder means whereby fluid under pressure from the tubing string andbores of the tubular sections is conducted to the piston and cylindermeans to actuate the same to thereby set the anchor and seal units,

means releasably securing said threaded means in its position inthreaded connection with the upper tubular section and engageable withthe lower tubular section, and

means nonrotatably connecting the lower section to the lower anchor andseal unit to restrain the lower section against rotation when the loweranchor and seal unit is in set position, whereby a rotation of the tubmgand upper section will actuate the threaded connectron between saidupper section and the threaded means to move the upper and lowersections axially of each other in a direction to move the lower abutmentin a direction to release the lower anchor and seal unit from its setposition.

7. A well packer assembly as set forth in claim 6,

0 together with seal means positioned between the lower external portionof the upper tubular section and the upper internal portion of the lowertubular section to direct the fluid under pressure through thecommunication means during setting, and

by-pass means comprising registering parts on the two tubular section-swhen said sections have been moved to a position unsetting the anchorand seal units for by-passing said seal means.

8. A well tool assembly adapted to be lowered on a tubing string andanchored Within a well bore including,

an upper tubular section secured to the tubing string and having anupper external abutment at its upper end,

a lower tubular section having a lower external abutment at its lowerend,

threaded means connecting said upper and lower sections against movementin an axial direction with respect to each other,

an upper anchor unit mounted on the upper section and confined againstupward movement by the upper abutment,

a lower anchor unit mounted on the lower section and confined againstdownward movement by the lower abutment,

hydraulically-actuated setting means between said upper and lower anchorunits for moving said units in directions toward the abutments to setsaid units into anchoring position,

mean-s for directing fluid pressure to said hydraulicallyactuatedsetting means to actuate the same and set the anchor units, and

means for releasably mounting the threadedmeans in a position connectingsaid upper and lower sections whereby the sections remain in connectedposition during the setting of said anchor units.

9. A well packer assembly as set forth in claim 8,

together with hydraulically-actuated means for releasing said threadedmeans from a position connecting the upper and lower sections wherebysaid sections may thereafter undergo axial movement in a directionmoving the upper and lower abutments away from each other to therebyrelease the lower anchor unit from its respective set position andpermit subsequent limited upward movement of the tubing string relativeto the upper anchor to release the same.

10. A well packer assembly as set forth in claim 8,

together with hydraulically-actuated means for releasing said threadedmeans from a position connecting the upper and lower sections wherebysaid sections may thereafter undergo axial movement in a directionmoving the upper and lower abutments away from each other to therebyrelease the lower anchor unit from its respective set position andpermit subsequent limited upward movement of the tubing string relativeto the upper anchor to release the same,

means for nonrotatably connecting the lower anchor unit to the lowertubular section to restrain said lower section against rotation when thelower anchor unit is set,

the upper tubular section and the tubing string thereabove beingrotatable relative to the lower section to actuate the threaded means tomove the upper and lower sections axially with respect to each other ina direction which moves the lower abutment downwardly to unset the loweranchor unit, said rotation of the upper section and tubing beingemployed for release in the event that there is a malfunction of thehydraulically-actuated releasing means for said threaded means.

11. A well packer assembly as set forth in claim 8,

together with hydraulically-actuated means for releasing and threadedmeans from a position connecting the upper and lower sections wherebysaid sections may thereafter undergo axial movement in a directionmoving the upper and lower abutments away from each other to therebyrelease the lower anchor unit from its respective set position andpermit subsequent limited upward movement of the tubing string relativeto the upper anchor to release the same,

means for nonrotatably connecting both the lower anchor unit and theupper anchor unit to the lower tubular section to restrain said lowersection against rotation when either or both of said anchor units areset,

the upper tubular section and the tubing thereabove being rotatablerelative to the lower section to actuate the threaded means to move theupper and lower sections in an axial direction which moves the upper andlower abutments away from each other and effects an unsetting of bothanchor units, said rotation of the upper section and tubing beingemployed in the event that there is a malfunction of thehydraulically-actuated releasing means for said threaded means.

12. A well packer assembly as set forth in claim 8,

35 together with hydraulically-actuated means for releasing saidthreaded means from a position connecting the upper and lower sectionswhereby said sections may thereafter undergo axial movement in adirection moving the upper and lower abutments away from each other tothereby release the lower anchor unit from its respective set positionand permit subsequent limited upward movement of the tubing stringrelative to the upper anchor to release the same,

a bore-closing element lowerable into the bores of the tubular sectionsand positioned to direct pressure fluid from the tubing string againstsaid hydraulicallyactuated release means and thereafter against one partof the hydraulically-actuated setting means in a direction to unset saidlower anchor unit.

References Cited by the Examiner UNITED STATES PATENTS 2/1964 Brown etal 166--120 X 7/1964 Brown 166120

8. A WELL TOOL ASSEMBLY ADAPTED TO BE LOWERED ON A TUBING STRING ANDANCHORED WITHIN A WELL BORE INCLUDING, AN UPPER TUBULAR SECTION SECUREDTO THE TUBING STRING AND HAVING AN UPPER EXTERNAL ABUTMENT AT ITS UPPEREND, A LOWER TUBULAR SECTION HAVING A LOWER EXTERNAL ABUTMENT AT ITSLOWER END, THREADED MEANS CONNECTING SAID UPPER AND LOWER SECTIONSAGAINST MOVEMENT IN AN AXIAL DIRECTION WITH RESPECT TO EACH OTHER, ANUPPER ANCHOR UNIT MOUNTED ON THE UPPER SECTION AND CONFINED AGAINSTUPSTREAM MOVEMENT BY THE UPPER ABUTMENT, A LOWER ANCHOR UNIT MOUNTED ONTHE LOWER SECTION AND CONFINED AGAINST DOWNWARD MOVEMENT BY THE LOWERABUTMENT, HYDRAULIC-ACTUATED SETTING MEANS BETWEEN SAID UPPER AND LOWERANCHOR UNITS FOR MOVING SAID UNITS IN DIRECTIONS TOWARD THE ABUTMENTS TOSET UNITS INTO ANCHORING POSITION, MEANS FOR DIRECTING FLUID PRESSURE TOSAID HYDRAULICALLYACTUATED SETTING MEANS TO ACTUATE THE SAME AND SET THEANCHOR UNITS, AND MEANS FOR RELEASABLY MOUNTING THE THREADED MEANS IN APOSITION CONNECTING SAID UPPER AND LOWER SECTIONS WHEREBY THE SECTIONSREMAIN IN CONNECTED POSITION DURING THE SETTING OF SAID ANCHOR UNITS.